One of the simplest and most beautiful experiments in aërostation, is
to take a turkey’s maw, or stomach, properly prepared, and to fill it
either with pure hydrogen gas, or the carburetted hydrogen produced
from coal. If the balloon be then allowed to escape in the open air, it
will ascend rapidly in the atmosphere: but the best method of showing
the experiment, is to let the balloon off a high staircase, and observe
it ascend to the cupola or light, where it will remain near the highest
point till the escape of the gas allow it to descend. The prepared maw
for this balloon may be purchased of any optician.